you can send that messy, dirty, smelly cash to me.

Did you make sure that all the browser settings are set to default settings? That doesn't make sense because you said it's happening in more than one browser. Care to try another one, like safari or opera just to check if you are getting the same strange behavior there? You can remove it after you test it for a day or two. That would be interesting just to see if it does the same thing or not. It would just be another data point.

I know what you can do. Try firefox in safe mode and see if it exhibits the same strange behavior. If it doesn't, that certainly points to a plug-in or add-on, and we can remove them all, and start over if that's the case. Do you know how to start FF in safe mode? There should be a menu item in the firefox folder under your start menu that says "Mozilla Firefox (Safe Mode)"

For IE, if you go to Internet Options (either from control panel, or IE/tools menu) on the advanced pane, there's a button to "Reset Internet Explorer Settings", with the explanation that it resets all IE settings to their default condition. However, I don't believe it removes plug-ins and add-ons, but it's worth trying, considering that this machine doesn't seem very usable in the state that it's in. It's up to you if you want to try that or not.

You mentioned the video card earlier in the thread. Are there any driver updates available for it? If you want to eliminate the video card, you could install a remote desktop product on it and try running it remotely. Something like vnc (install the server on this machine, and the client on another machine, run the client on another machine to connect to the server, and you will see your desktop on the machine running the client) or gotomy pc trial. For vnc, there's realvnc or tightvnc. Either one is free. You just need to know the local IP address of the machine you are checking to connect to it from the client machine when you are on the same local area network.

-David